Commutator and method of assembling same



Si N. SLO/N COMMUTATOR AND METH ASSEMBLIES SAFYIE,

APPLICATWH FILED MAR. 3, 191.

[UNITED STATES PATENT OFFICE.

SEBASTIAN N. SLOAN', OF MAUMEE. OHIO, ASSIGNOR TO THE TOLEDO STANDARDCOMMUTATOR 00., OF TOLEDO, OHIO. -A CORPORATION- OF OHIO.

COMMUTATG'B AND METHOD OF ASSEMBLING SAME.

Application filed March 3.

Methods of Assembling Same; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying d awings, and to theletters and figures of reference marked thereon, which form a part ofthis specification.

. In the assembling of the numerous parts which go to make up acommutator for an electric dynamo or motor. it is necessary that thealternating segmental bars and insulating pieces be relatively disposedwith great accuracy and that they be held rigidly against displacementeither radially or longitudinally, since such movement of either of theparts might cause short circuits. or

grounds and other accidents.

The usual method of building up a commutator is. briefly. to gather thecopper segments, separated by corresponding mica segments, intocylindrical form in a stout ring or former leaving an axial hole for theshaft. These segments have. respectively. at each end angular notcheswhich, taken collectively, form deep circular channels in the ends ofthe cylinder. Into these channels are forced stout steel rings which areshaped in cross-section to conform to the channels, there being, ofcourse. insulating material between the rings and the copper segments.The centrifugal pressures upon the segments due to the many thousandrevolutions per minute now required in smalhelectric mo tors is verygreat. Therefore the inward pressure upon the rings amounting, in modernpractice to many tons, necessary to bring the several parts into theirfinal relative positions and to there rigidly and immovably retain them.is so great that frequently the points or tangs.-formed in the coppersegments by the angular notches above referred to,as well as the inneredges of the segments, are distorted or caused to flow and to overlap orpenetrate the adjacent insulation and to contact .with the neighboringcopper. This mishap renders the commutator inoperative until theaccidental contact is discovered and corrected. This in- Specificationof Letters Patent.

1917. Serial No. 152.239.

volves undue time and labor and ofttimes results in the throwing away ofthe Work.

My invention relates to new and. useful improvements in commutatorconstruction, the main objects being to overcome the difiir-ulties andfruitful source of trouble here pointed out. and, more particularly, tofurnish an unyielding support for the inner edges of the segments andfor the segmenttangs throughout their length against distortion due tothe end-pressure of the steel clamping-rings; to prevent radial movementof the copper segments under the endpressure of the clamping-rings; toprevent movement of mica insulating-rings as well as the movement oftheir natural and artificial laminae upon each other, and to provide animproved insulation for the various parts of the commutator.

In the accompanying drawings are illustrated means for practising myinvention.

- )er se ments 1. includin the tan s 2 shall t: i l! h not be displaceddistorted by the great end-pressure of the clamping-rings 3, I havefound that these edges shouldbe rigidly supported throughout theirlength during and after the application of the pressure upon theclampingrings which are to hold the segments in fixed, operativerelation. The several copper segments 1, With the usual interposed micasegments, are assembled in a forming ring in the usual Way. Channeledmica rings tare fitted into the circular grooves formed by the notches 5in the copper segments. A sleeve 6 formed, preferably. integral with oneof'the clamping-rings extends through the axial shaftopening 7. Betweenthe outer surface of this sleeve and the inner edges of the segments 1is an annular space 8. By means of a suitable press the clamping-ringsare given apreliminary squeeze toward each other, bringing the partsnearly into their ultimate relation, through the wedge-like action ofthe angular surfaces of the rings upon the opposed correspondingsurfaces of the end:

' ments at their inner edges vent their chstortio'n un grooves of thedevice.

' menslons as to fill fies, becomes exceedingly hard (as for instance,

The several parts and the manner of assembling them thus far referredto, as well as the instrulnenetalities eemployed, are well understoodand need not be here further illustrated or explained.

N ow, as above explained, it becomes necessary to rigidly support thecopper segin order to pre- ..c1' the severe final squeeze of theclampingrings. To this end the sleeve 6 is )rovided "with a series ofholes 9 leading t rough the sleeve into the annular space 8. Projectingupwardly from a base ll), is a cylindrical plug 11 of such dithe shaftopening 7 up to near the holes 9. A plunger 12, actuated by any suitablemechanism, is arranged to enter and operate in the upper part of theshaft'opening in opposition to the plug 11. A substance which can bemade to assume a liquid or semi-liquid state, and which solidior whensuitably treated solidifies and bakelite, hereinafter mentioned) isinserted while'in a soft state into the opening 7 on top of the plug 11.The plunger 12 follows, forcing the soft material through the holes 9,and under pressure filling the annular space 8 and all of itssurrounding crevices and'interstices. Subsequently the plunger 1swithdrawn and after this material has as same-d its solidified state,the final pressure is given to the clamping rings, operation the tangs 2andthe inner edges of the segments 1, unyieldingly supported asdescribed, maintain their shape and relative tainable as bakelite.

positions. The outer end of the sleeve is peaned over the clamping ring,through which it protrudes, as at 13, and now all of the parts aresecurely fastened in proper and fixed relation, and when the hardenedmaterial left inthe shaft-opening is bored out the work is complete.

The'material which for filling the vacancies around the sleeve 6 iscommercially 'knownand is readily ob- As is well known, this materialcan be obtained in a soft or plastic state and .on being heat treated orbaked becomes exceedingly hard. It also forms an admirable insulator.Other substances which are nonconductors and'which are fluidal or solidunder varying conditions will suggest themselves to those skilled in theart and I do not therefore limit my invention to the material. referredto.

aving descr bed my invention, what I claim and desire to secure byLetters Patent,

1. In a commutator. a group of insulated from each other, a holdercomprising a sleeve or segments barrel extending through the group ofsegments, a pair 0t during which.

I find best adaptedtherefor 2. In a commutator, a series of segments incylindrical format1on,a supportingsleeve extending co-axially with thecommutator through the segments, end clamping rings at the ends of thesegments and forced :together so as to tightly clamp the segmentsandhold them from axial and radial displacement, insulation between thesegments and between the clamping rings-and the segments, and betweenthe sleeve and the inner edges of the segments a solidified insulatingmedium which supports said segments and said insulation from distortiondue to the 5 pressure-of the clamping rings. 3. In a commutator, aseries of cylindrically arranged segments suitably insu-: lated fromeach other, a supporting sleeve extending co-axially-with the commutatorthrough the segments, end clamping rings at the ends of the segments andforced together so as to tightly clamp the segments and hold them fromaxial and radial displacement,- insulation between the clamping ringsand the segments, and between the sleeve and the inner edges of thesegments a hard insulating medium to support said segments and saidinsulation fromdistortion due to the pressure of". the clamping rings. I

s an article of manufacture, a commutator comprising a series ofradially disposed segments insulated from each "other and provided attheir ends with notches which collectively form circular channels in theends of the assembled segments, insulating rings in said circularchannels, clampng rings engaging said insulating rings, an1nternalsleeve co-axial with 'the commutator, there being an annularspace between the sleeve and. the inner edges of the segments, and asolidified insulating'substance which. is provided in said annular spaceso as to support theinner edges of. the segmentsagainst distortion dueto the pressure of the clamping rings.

in presence oftwo witnesses.

SEBASTIAN N. SLOAN. Witnesses: I

Louis JAcoBsoN, LUUYS A. ALEXANDER.

